How do you find the radius of a circle if you have the circumference?

Question

Find the radius of the circle.
Circumference = 62.8 mi

9622 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-05-25T14:38:09

A formula for the circumference of a circle is:

$C = 2 π r$ $C = 2pir$

Solve the formula for r:

$r = \frac{C}{2 π}$ $r = C/(2pi)$

Substitute in the given circumference.

Given $C = 62.8 mi$ $C = 62.8" mi"$

$r = \frac{62.8 mi}{2 π}$ $r = (62.8" mi")/(2pi)$

$r = 9.995 mi$ $r = 9.995" mi"$